If you have excessively thinning areas or a low-density hairline, Hair Booster is an intensive, vitamin-enriched leave-in scalp treatment that exfoliates dead skin cells and transports advanced nourishment to hair. How to use Use twice daily. Apply Hair Booster directly onto scalp. Distribute with fingertips to areas of excessively thin-looking hair and along the hairline. Vitamin enriched formula gives temporary redness to skin after application.